Rock-drill.



N0. 638,856. Patented Dec. I2, |899.

` G. S. ULLATHURNE & H. P. VACHER.

BUCK DRILL.

(A I" med J 25,1899. (N0 Mdel.) PP canon m nrrnn PATEN'r ROCK-DRILL.

SPECIFICATION forming part of Ltters Patent No. 638,856, dated December 1e, ieee. Application filed January 25,1899. Serial No. 703,383. (No model.)

T all wwnt it may con/067%:

Be it known that we, GRANVILLE SHARP UL- LATHORNE and HERBERT PERKINS VACHER, of the city of London, England, have invented certain new and useful Improvements in Rock-Drills, (for which we have obtained Letters Patent of Great Britain, dated October l0, 1898, No. 2l,282,) of which the following is a full, clear, and exact specication, referenceV motive fluid and in which the boring-tool is coupled or otherwise secured to the pistonrod of the machine; and it consists of the hereinafter-described construction of such drill, wherein the piston acts as a slide-valve opening and closing inlet and exhaust ports of the cylinder and also regulates the distribution of the motive fluid in the cylinder as required to effect its motion.

The drill consists of a working cylinder ct, closed on both ends by suitably-shaped covers and provided with inlet-ports o and p and with exhaust-ports a chest c located on one side of the cylinder, approximately in the middle thereof, piston b, fitted in the cylinder, piston-rod d, integral with or rigidly secured to the piston, a cutter or bit rigidly coupled to the piston-rod d, and a device for imparting to the piston a partly rotary motion in its stroke, and which may be either such as the twisted or riiled stud lo, engaging with the correspondingly-shaped sleeve mas shown in the drawings, or some other equivalent device suitable for the purpose. Working cylinder a is of the usual shape employed for this purpose. Chest c is partly integral therewith and closed by covers c', secured thereto by screws c2. This chest c is connected to a boiler, air-compressor, or other source of expansive liquid and communicates with the interior of the cylinder through the ports o and 5o p. Piston b iills about two-thirds of the length of the interior of the working cylinder and is provided with two annular recesses r and s, concentrical bores fand g, and ports f,f2, and g. The annular recesses r and s are l-ocated correspondingly to the position of the inlet-ports o and p and of the exhaust-ports x. Ports f and g constitute passages between the spaces created by the annular recesses r and s of the piston and the bores f and g, respectively. Bore g opens toward the space a2 between the rear end of the piston Z1 and the cover o of the cylinder, whereas bore f communicates with the space a in front of the piston. Plug ,e closes up boref and divides it from bore g. Ports o andp are equidistant or approximately equidistant from exhaust-ports a', which are located between them, and the distance between the centers of the annular recesses r and s corresponds approximately to that between the eX- haust-ports :o and either of the ports o and p.

In the position shown in Fig. l the piston is at the end of its return stroke, and, as will be observed in the drawings, there is asmall space d2 left between the rear end of the piston and the cover o, which, as stated above, communicates with the bore g of the piston. In this position the annular recess s stands opposite the inlet-ports p and the annular recess r opposite the exhaust-ports x.' The motive iiuid flows then from chest c,through ports p and r', into the bore g and space a2 in the rear of the piston and exerts its pressure upon it and drives it forwardly, while the expanded motive iiuid escapes from the space ce in front of the piston, through the passages f2, into the bore f, and, through the passages f', into the annular space formed by recess 'l' and exhaust-ports Qc. As the 'piston advances on its forward stroke it closes ports p, but not until a sutlicient quantity of the motive fluid has been admitted in the working cylinder to drive the piston for the full length of its stroke. At the end of its forward stroke the relative positions of the ports of the cylinder and of the piston are reversed. The annular recess r is then situated opposite the inletports o and the motive fluid iiows through these inlet-ports and passages f into the bore fand through portsf2 into the space d in frontof the piston, while the expanded fluid escapes from space a2 through bore c, communicating through ports g' andthe annular recess s with the exhaust-ports of the cylinder. The motive Huid thus escapes from the space a2, While a fresh chargeis admitted, as explained above, into the space d' in front of the piston. This fresh charge drives the piston on its return stroke, and when the end of its stroke is reached the cyclus of action is repeated, as explained above.

'Machines of this kind have to stand rough handling and almostincalculable concussons While Working. It is therefore of great advantage if delicate parts, such as slides or valves generally, can be avoided in 'their construction.

It is not a question of economy or highest lpossible utilization Aof the motive Iiuid in Itheir operation, but vthe most durable construction, and one that will withstand the greatest possible Wear, which is the desidera- -tum of the users of such machines.

It will be seen that in the above-described construction there are practically no .parts that can in any manner be `affected by jolt- .ing or concussions, and consequently thata vdrill of the construction described -s practi cally indestructible and certainly not liable to .be disabled by disarrangementof its parts.

This is the most important merit of our ininder closed on both ends by suitable covers and having inlet and exhaustports located approximately equidistantly from each other, a chest inclosing the inlet-ports, a piston fitted in the Working cylinder and provided with a concentrical bore and two annular recesses impositions approximately corresponding to the relative position of the inlet and exhaust ports of .the cylinder, a plug set in the bore of the piston between the two annu-` lar recesses, passages connecting the bore of the piston With the annular recesses in the body of the piston and With .the interior of the cylinder, one with that in front and the other with that in the rear of the piston, and a piston-rod journaled in one cover of the Working cylinder.

2. The Vcombination `ot .the -vvorkingcylin derd closed on-'both ends.by;suitablyshaped covers 'and provided'with vinlet-ports-,o and@ and AWit-h exhaust-:ports x, chest c, piston b, provided with the annular'recesses rand s, concentricalbores fand g and portsffand f2 and g', piston-rod d and of meansffor imparting apartly-rotary reciprocating motion to the piston at each stroke.

GRANVILLE SHARP ULLATHORNE. 4IlERBEll-Tl PERKINS VACHER.

Witnesses:

HARRY A. WISE, JOSEPH I-IUDsrITH.. 

